Washington: The US is keen on working with Pakistan in a "cooperative fashion" to tackle many common challenges, including extremism and terrorism, a senior official has said.

"We have a keen interest in working with Pakistan to address the many common challenges that we face. We feel that working together, we can address concerning issues of extremism and combating terrorism," Assistant Secretary of State for Public Affairs Mike Hammer told foreign journalists.

The US is always looking for a path forward where the two countries' interests meet to see how they can most effectively advance these common interests, he said.

Secretary of State Hillary Clinton, he said, is herself very personally involved in working with her Pakistani counterparts to advance interests that the US leadership feels are important for both the countries.

"So we will be looking again for mechanisms. But the general principle is that I think there's recognition on the part of both governments that these are problems that are best faced when we work together in a cooperative fashion and that it serves both country's interest as the threat of terrorism, threat of extremism, leads to horrific casualties not only for Pakistan, but obviously concerns for the United States, our partners and allies," Hammer said.

The only way to overcome these is by increasing cooperation between the two sides and "making sure that we are in sync in these efforts," he said in response to a question.

State Department spokesperson Victoria Nuland said the two countries are now having an intense counter-terrorism relationship.

"The Secretary (of State) spoke about our efforts against terror with Pakistan when she saw Foreign Minister (Hina Rabbani) Khar here just a couple of weeks ago. We have an intense counter-terrorism relationship," she said.

"We would like to do even more together. We're continuing to try to work on these issues and encourage our Pakistani partners to do as much as they can against these issues, because Pakistanis are the greatest victims of terror inside their own country," Nuland said.